KeyedDecodingContainerProtocol+DefaultValue.swift

import Foundation

extension KeyedDecodingContainerProtocol {
    /**
     Decodes a value of the given type for the given key, providing a default value if the value could not be decoded.

     - parameter type: The type of value to decode.
     - parameter key: The key that the decoded value is associated with.
     - parameter defaultValue: The default value that is used if the a value for `key` could not be decoded.

     - returns: A value of the requested type, if present for the given key and convertible to the requested type, or `defaultValue` if the value could not be decoded.
     */
    func decode<T>(_ type: T.Type, forKey key: Self.Key, defaultValue: T) -> T where T : Decodable {
        return (try? decode(type, forKey: key)) ?? defaultValue
    }
}